1. Field of the Invention
This invention relates to an animal feed supplement and, in particular, to an animal feed supplement in solid form.
2. Brief Description of the Prior Art
The value of carbohydrate-containing supplements as an energy source in animal diets has been recognized for many years. Phosphoric acid has often been added to supplements to serve as a preservative and as a source of dietary phosphorous, and urea has been added to ruminant feed supplements to supply nonprotein nitrogen. Fats have been included in these supplements as described in U.S. Pat. No. 2,793,952, and vitamins have also been used as described in U.S. Pat. No. 2,807,546. Most of the aforementioned animal feed supplements have been employed as a liquid which must be mixed with the animals' feed rather than permitting free choice feeding.
Attempts have been made to prepare these supplemental feeds as solids. Typical of these are salt blocks, mineral blocks, protein blocks and molasses blocks. The feed blocks offer the advantage of free choice feeding of animals, thereby reducing the labor and expense otherwise incurred to mix the feed supplement with the animals' feed ration. These blocks have, heretofore, been manufactured by compressing ingredients into a molded shape or by evaporative heating of the ingredients. Both methods have disadvantages; the compressed blocks have limited contents of energy-supplying ingredients such as molasses and fat, and heat-sensitive vitamins and the like may be partially oxidized and/or decomposed by evaporative heating.
U.S. Pat. No. 3,420,672, discloses the formation of stable emulsions of edible fats in a molasses-containing feed supplement with a starch emulsifying agent. The patent also discloses that the use of relatively large amounts of starch, e.g., around 6 percent, solidifies the compositions. It is desirable to reduce the quantity of starch necessary for solidification of the fat-containing molasses feed supplement and to impart a substantial water resistance to the compositions. Additionally, it is desirable to provide the proper proportions of edible fat and a sugar source such as molasses for the energy requirements of the animals while maintaining sufficient palatability to permit the free choice feeding by animals. When the composition is intended for use with ruminants, the composition can also contain the necessary quantity of nonprotein nitrogen in the form of urea to supply the ruminants' dietary protein requirements.
A recent development has been the discovery that the addition of a soluble phosphate to the feed supplement together with a soluble source of calcium, such as calcium chloride, sulfate or oxide, results in an in-situ reaction which can solidify the feed supplement into a solid block form.
Although calcium oxide is a preferred material for this purpose, it does not permit as facile a reaction as can be achieved with more soluble sources of calcium. Additionally, it was discovered that optimum hardness of the resultant product can be achieved with calcium oxide only when supplemental amounts of a starch additive are employed, the latter undesirably increasing the cost of manufacture of the product.